He hurried to the booking office only _____ that all the tickets had been sold out. [ ]

Jack, I haven’t seen your brother for a long time．—- He ________Shanghai on business for two months．

The final score of the basketball match was 93:94. Wewere only ___ beaten.

Where’s Li Hua?—Look! He _______ tennis on the playground.

I think ____necessary for us _____the birds.